Network Working Group B. Whetten
Request for Comments: 3048 Talarian
Category: Informational L. Vicisano
Cisco
R. Kermode
Motorola
M. Handley
ACIRI 9
S. Floyd
ACIRI
M. Luby
Digital Fountain
January 2001
Reliable Multicast Transport Building Blocks for One-to-Many
Bulk-Data Transfer
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
Abstract
This document describes a framework for the standardization of bulk-
data reliable multicast transport. It builds upon the experience
gained during the deployment of several classes of contemporary
reliable multicast transport, and attempts to pull out the
commonalities between these classes of protocols into a number of
building blocks. To that end, this document recommends that certain
components that are common to multiple protocol classes be
standardized as "building blocks". The remaining parts of the
protocols, consisting of highly protocol specific, tightly
intertwined functions, shall be designated as "protocol cores".
Thus, each protocol can then be constructed by merging a "protocol
core" with a number of "building blocks" which can be re-used across
multiple protocols.
Whetten, et al. Informational [Page 1]RFC 3048 RMT Building Blocks January 2001Table of Contents
1 Introduction .................................................. 2
1.1 Protocol Families ........................................... 5
2 Building Blocks Rationale ..................................... 6
2.1 Building Blocks Advantages .................................. 6
2.2 Building Block Risks ........................................ 7
2.3 Building Block Requirements ................................. 8
3 Protocol Components ........................................... 8
3.1 Sub-Components Definition ................................... 9
4 Building Block Recommendations ................................ 12
4.1 NACK-based Reliability ...................................... 13
4.2 FEC coding .................................................. 13
4.3 Congestion Control .......................................... 13
4.4 Generic Router Support ...................................... 14
4.5 Tree Configuration .......................................... 14
4.6 Data Security ............................................... 15
4.7 Common Headers .............................................. 15
4.8 Protocol Cores .............................................. 15
5 Security ...................................................... 15
6 IANA Considerations ........................................... 15
7 Conclusions ................................................... 16
8 Acknowledgements .............................................. 16
9 References .................................................... 16
10 Authors' Addresses ........................................... 19
11 Full Copyright Statement ..................................... 20
1. Introduction
RFC 2357 lays out the requirements for reliable multicast protocols
that are to be considered for standardization by the IETF. They
include:
o Congestion Control. The protocol must be safe to deploy in the
widespread Internet. Specifically, it must adhere to three
mandates: a) it must achieve good throughput (i.e., it must not
consistently overload links with excess data or repair traffic),
b) it must achieve good link utilization, and c) it must not
starve competing flows.
o Scalability. The protocol should be able to work under a variety
of conditions that include multiple network topologies, link
speeds, and the receiver set size. It is more important to have a